In aircraft, there are normally unavoidable discontinuities in the outer skin. Such discontinuities occur, for example, at the interface of adjacent panels and where access panels or doors are formed in the skin. In many situations, it is desirable to seal these discontinuities and/or provide a continuous electrical path along the outer surface of the skin across the discontinuities. Known methods for sealing a discontinuity include filling the discontinuity with putty and covering it with metallic tape. This method presents a number of problems. These problems include a time consuming installation procedure and a tendency of the seal to fail when the aircraft is in flight. In addition, this type of seal cannot be removed without destroying it, and the destructive removal procedure is time consuming. Efforts to develop an acceptable reliable seal have been complicated by the fact that normally access is available from the outside of the skin only.